feat(eval): memoir A/B chapter judging and eval-web parity with dialogue

- Judge baseline excerpt and library chapter separately; build_memoir_compare_summary for gate, nine-dim and leaf deltas.

- Memoir SSE chapter payload: baseline_judge, compare_summary, baseline_judge_error.

- MemoirJudgeOutput: loose score coercion and post-validate clamp; memoir judge prompt caps from settings.

- app-eval-web: two-column MemoirScoreCard layout, MemoirCompareSummary, chapter blocks and CSS.

- Add memoir_compare_summary, log_events, celery_log_context, memoir_pipeline_progress; tests and migration 0014.

- Misc: memory/evidence and enrichment paths, task/orchestrator updates, internal-eval docs, env examples.

api/app/core/log_events.py

@@ -0,0 +1,131 @@
+"""结构化日志辅助：统一 ``event=`` 行格式与 Celery prerun 可提取的上下文字段。"""
+
+from __future__ import annotations
+
+from typing import Any
+
+
+def format_log_event(event: str, **fields: Any) -> str:
+    """
+    生成单行 ``event=...`` 日志正文：``event`` 固定首位；``msg`` 固定末位（若提供）；其余键按字母序。
+
+    ``None`` 与空字符串会跳过；浮点数默认保留一位小数（适用于 ``duration_ms``）。
+    """
+    parts: list[str] = [f"event={event}"]
+    keys = sorted(k for k in fields if k != "msg")
+    ordered = list(keys)
+    if "msg" in fields:
+        ordered.append("msg")
+    for k in ordered:
+        v = fields[k]
+        if v is None:
+            continue
+        if isinstance(v, float):
+            parts.append(f"{k}={v:.1f}")
+        elif isinstance(v, bool):
+            parts.append(f"{k}={str(v).lower()}")
+        else:
+            s = str(v).strip()
+            if not s:
+                continue
+            parts.append(f"{k}={s}")
+    return " ".join(parts)
+
+
+def correlation_bind_kwargs(
+    *,
+    user_id: str | None = None,
+    memoir_correlation_id: str | None = None,
+    correlation_id: str | None = None,
+    **more: str | None,
+) -> dict[str, str]:
+    """供 ``logger.bind(**...)``：``memoir_correlation_id`` 会以 ``correlation_id`` 写入（统一检索键）。"""
+    out: dict[str, str] = {}
+    uid = (user_id or "").strip()
+    if uid:
+        out["user_id"] = uid
+    cid = (correlation_id or memoir_correlation_id or "").strip()
+    if cid:
+        out["correlation_id"] = cid
+    for k, v in more.items():
+        if v is None:
+            continue
+        s = str(v).strip()
+        if s:
+            out[str(k)] = s
+    return out
+
+
+# bind=True 任务的 positional 与字段名映射（kwargs 优先，缺位再填）
+_TASK_POSITIONAL_FIELDS: dict[str, tuple[str, ...]] = {
+    "app.tasks.memory_enrichment_tasks.enrich_memory_source": ("user_id", "source_id"),
+    "app.tasks.memory_compaction_tasks.memory_compaction_run": ("user_id",),
+    "app.tasks.chapter_compose_tasks.recompose_chapter": ("chapter_id",),
+    "app.tasks.memoir_quality_pass_tasks.memoir_quality_pass": ("user_id",),
+    "app.tasks.memoir_tasks.process_memoir_phase2": ("user_id", "chapter_category"),
+    "app.tasks.memoir_tasks.process_memoir_phase1": ("user_id",),
+    "app.tasks.memoir_tasks.generate_chapter_content": ("user_id", "stage"),
+    "app.tasks.chapter_cover_tasks.generate_chapter_cover": ("chapter_id",),
+    "app.tasks.story_image_tasks.generate_story_image": ("story_id",),
+    "app.tasks.story_title_tasks.generate_story_title_after_create": (
+        "story_id",
+        "chapter_category",
+        "oral_scope",
+        "user_id",
+    ),
+}
+
+_KW_KEYS_COPY: tuple[str, ...] = (
+    "user_id",
+    "source_id",
+    "chapter_id",
+    "story_id",
+    "chapter_category",
+    "stage",
+    "oral_scope",
+)
+
+
+def celery_prerun_extras(
+    task_name: str | None,
+    args: tuple[Any, ...],
+    kwargs: dict[str, Any] | None,
+) -> dict[str, str]:
+    """
+    从 Celery ``task_prerun`` 的 args/kwargs 提取 ``user_id``、``correlation_id`` 等，
+    供 ``set_celery_log_extras`` 与任务体内 loguru 记录关联。
+    """
+    out: dict[str, str] = {}
+    kw = dict(kwargs or {})
+
+    mcid = kw.get("memoir_correlation_id")
+    if mcid is not None:
+        s = str(mcid).strip()
+        if s:
+            out["correlation_id"] = s
+
+    for key in _KW_KEYS_COPY:
+        if key not in kw:
+            continue
+        val = kw[key]
+        if val is None:
+            continue
+        s = str(val).strip()
+        if s:
+            out[key] = s
+
+    name = (task_name or "").strip()
+    fields = _TASK_POSITIONAL_FIELDS.get(name)
+    if fields and args:
+        for i, field in enumerate(fields):
+            if i >= len(args):
+                break
+            if field in out:
+                continue
+            val = args[i]
+            if val is None:
+                continue
+            s = str(val).strip()
+            if s:
+                out[field] = s
+    return out